Tortoise taphonomy and tortoise butchery patterns at Blombos Cave, South Africa

Abstract

a b s t r a c tTortoises are one of the most common faunal components at many Palaeolithic archaeological sites across the Old World. They provide protein, fat, and other 'animal' resources in a 'collectable' package. However, for most sites their interpretation as human food debris is based only on association, rather than demonstrated through taphonomic analysis. Because of their very different anatomical configuration compared to mammals, it is difficult to conduct such analyses by directly applying the taphonomic methods used to interpret large mammal assemblages. Tortoise-specific taphonomic analysis is presented here for the Still Bay layers at the important Middle Stone Age (MSA) site of Blombos Cave (BBC), Western Cape, South Africa. Research on MSA subsistence systems at sites such as BBC has almost exclusively relied on analysis of large ungulate remains, in spite of the fact that many of these key sites contain equal or greater numbers of tortoise fragments. In this analysis we show that human modification is common on the BBC tortoises, and that there are consistent patterns of fragmentation and burning that indicate set processing sequences including cooking while in the shell, hammerstone percussion, and human chewing of limbs. The almost exclusive dominance of the angulate tortoise, Chersina angulata, is confirmed by full skeletal element analyses rather than only counts of single elements such as humeri. The sex distribution can be reconstructed for this species, and is female-biased. For all tortoise assemblages, taxonomic and skeletal element abundance data should be calculated from a sample of complete elements, or at minimum the entoplastron and humerus. A sample of shell and limb/girdle elements should also be subjected to microscopic bone surface modification analysis, as modifications are often rare or subtle but highly informative. Using this approach, analysis of breakage patterns, bone surface modification, and burning patterns can be understood together to specifically reconstruct tortoise collection, processing, and human dietary significance across a range of archaeological sites.

Pleistocene large reptile tracks and probable swim traces on South Africa’s Cape south coast

“…Literature on Pleistocene reptiles from the Cape south coast from archaeological sites relates to small reptiles (tortoises). 41,42…”

The origins and early elaboration of projectile technology

“…However, there is no consensus about how each hominin hunted or how to best interpret variability in faunal exploitation strategies . Early modern human sites such as Sibudu Cave and Klipdrift Shelter in South Africa show an abundance of smaller ungulates that may have been acquired through traps or snares, while others show either a preponderance of large ungulates or a shift over time in accumulation patterns of small and large fauna . The demand to explain this variation has steered zooarcheological work toward understanding the processes underlying the adoption of new technological solutions, one of which is the use of projectile technology.…”

Shellfishing and human evolution

“…The especially rich Klasies River Caves are in fact probably much better known for their extensive mammalian fauna than for their shellfish (Bartram and Marean, 1999;Binford, 1984;Klein, 1976Klein, , 1989Outram, 2001;Turner, 1989). In addition to mammals, the MSA inhabitants of Klasies River and other coastal sites accumulated numerous seabirds (Avery, 1990), particularly penguins and cormorants, and MSA people on the drier western stretches of the coastal zone also focused heavily on tortoises (Steele and Klein, 2005/06;Thompson and Henshilwood, 2014). At Ysterfontein 1, in what was probably an exceptionally arid area, they frequently collected ostrich eggs (Avery et al, 2008).…”